Dheeraj Pal1*, Nongthombam Boby1, Gurpreet Kaur2, Syed Atif Ali2, Satish Kumar1 and Pallab Chaudhuri2

1 Division of Animal Biotechnology, Indian Veterinary Research Institute, Izatnagar – 243122, India .
2 Division of Bacteriology, Indian Veterinary Research Institute, Izatnagar – 243122, India.

Received on 10 August 2016 and accepted on 01 September 2016



Gold nanoparticles (AuNPs) plasmon changes, as a result of additives and their follow up reaction in solution around zeta space of AuNPs, have been extensively used for analyte detection. Biomolecules like protein or nucleic acid, in conjugated or non-conjugated forms with AuNPs, when allowed to react with complimentary molecule such as antibody or nucleic acid target, lead to visual colour changes and may offer diagnostic test. Using synthetic nucleic acid probes, specific to complimentary target gene in a microbe, conjugated probe-AuNPs were exploiting Au-S bond chemistry. Thiolated nucleotide probes were successfully conjugated on AuNPs to prepare gold reagents that reacted specifically with complimentary gene target and not with non-complimentary sequence, the later failed to stabilise the probe-AuNPs and gave red to blue colour changes in solution after addition of salt. This rapid colour change of probe-AuNPs solution is able to differentiate the presence of complimentary and non-complimentary gene target in test solution, thus offer a strategy for detection of microbial genes.


 Gold nanoparticle, visual detection, Brucella, surface plasmon resonance.